This is a Congressionally mandated study to determine whether the children exposed to chloride deficient formula in 1978 and 1979 may have suffered some long-term effects which may be expressed in delayed motor and mental development or decreased school performance. This project is currently receiving support services from SAIC, Inc. (formerly JRB Associates). The activity of the past year has centered on 1) identifying subjects eligible for study as cases, 2) investigating the potential problems exposed children may have, 3) defining the test battery that cases and controls will undergo, 4) planning a pilot study to test study procedures including the selection of controls, and 5) securing the input of an interdisciplinary panel of physicians, psychologists and methodologists. Case finding has consisted of surveys of pediatric nephrologists, pediatricians in several states and a systematic CPHA search. Problem identification has consisted of the careful review of several hundred potential case records, a literature review, discussion with physicians who have treated cases, and a review of problems as described by parents. In subsequent years arrangements will be made to examine the study children and appropriate comparison children in order to assess the long term effects of exposure to chloride-deficient formula.